Alert archive / Pennsylvania / Mesoscale Discussions in 2017
Mesoscale Discussion 291
The Storm Prediction Center issued this mesoscale discussion at Mar 13, 2017, 10:01 PM EDT for 5 states. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 13, 2017, 10:01 PM EDT (02:01 UTC)
- Expired
- Mar 14, 2017, 2:00 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 47 counties
Baltimore County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Washington County, MD, Warren County, NJ, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Schuylkill County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Warren County, VA, Berkeley County, WV, Hampshire County, WV, Jefferson County, WV, Morgan County, WV
The radar
The Sterling radar (KLWX), 85 km from the middle of the area, began a volume at 02:01 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 2.0 hours before the alert went out and 85 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 781 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 46 m²/s²
- 0-3 km storm-relative helicity
- 453 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 14, 3:22 AM EDT | Mesoscale Discussion | SPC | Allegany, Baltimore, Carroll, Cecil, Frederick, Garrett and 5 more | 5 hr |
| Mar 14, 9:04 AM EDT | Mesoscale Discussion | SPC | Bergen, Essex, Hunterdon, Morris, Passaic, Somerset and 3 more | 4 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in Virginia, 2017Mesoscale Discussions in Maryland, 2017Every mesoscale discussion in 2017
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.